1. Field of the Invention
This invention relates to a non-impact recording method in which either characters or images are formed in response to an image signal with Joule heat generated by a selective electrical energization of either a conductive recording medium or a recorded member, and more particularly a non-impact recording method in which either the same characters or images can be formed concurrently on a plurality of overlapped conductive recording media. This invention also relates to a conductive recording medium for use in the above non-impact recording method.
2. Description of the Prior Art
In the prior art, as means for forming, copying and recording the same characters or images concurrently on a plurality of recording media, an impact dot type printer is frequently used. In this impact dot type printer, the copying and recording can be attained by applying a mechanical striking force against the recording medium to generate color in a pressure-sensitive coloring agent coated on a substrate of the recording medium or by transferring pressure-sensitive transfer ink to another recording medium.
However, such an impact dot type printer as described above still has some problems of reducing vibration or noise generated by mechanical striking action, reducing its size, weight and reducing amount of electrical power consumption caused by a capacitive restriction of a power supply of battery cell which are required in the case that the printer is to be assembled into portable type information equipment, in particular.
In view of the foregoing, as means for attaining concurrently a copying and a recording on a plurality of overlapped recording media or recorded members in a so-called non-impact dot type printer, a thermal processing type technology has already been disclosed in the gazettes of Japanese Patent Laid-Open Nos. Sho 52-115229 and 56-75894, and in particular, an ink-jet technology has already been disclosed in the gazettes of Japanese Patent Laid-Open Nos. Sho 51-24833 and 55-69463 and Japanese Patent Publication No. Hei 2-37307.
At first, the technology described in the gazette of Japanese Patent Laid-Open No. Sho 52-115229 as a thermal processing system is constructed such that there are provided a first recording sheet having at a front surface of a substrate a thermo-sensitive coloring layer and at a rear surface of it both an ink immersion preventive layer and a thermal fusing ink layer and a second transferring recording sheet overlapped on the recording sheet, wherein a thermal head is contacted with the surface of the first recording sheet to cause the thermo-sensitive coloring layer to generate color and form an image and concurrently the thermal fusing ink at the rear surface is transferred to the second recording sheet so as to attain a copied image. A technology concerning an improvement of the recording medium used in such a copying and recording system is already described in the gazette of Japanese Patent Laid-Open No. Sho 56-75894.
Then, a technology described in the gazette of Japanese Patent Laid-Open No. Sho 51-24833 as an ink-jet system is operated such that a part of liquid ink particle struck against the first recording sheet having a high ink permeation is permeated and absorbed in the second recording sheet having a high ink permeation overlapped on its rear surface so as to attain a copied image. In addition, the technology described in the gazette of Japanese Patent Laid-Open No. Sho 55-69463 is operated such that the heated ink particle is adhered to the first recording sheet and then a copied image is produced by a thermo-sensitive recording system subsequent to the second recording sheet overlapped on the rear surface thereof by heat energy carried by the ink particle. Additionally, the technology described in the gazette of Japanese Patent Publication No. Hei 2-37307 is operated such that liquid droplets of volatile coloring induced solvent is adhered to the first recording medium coated with coloring substance reacted with the liquid droplets, the residual non-reacted coloring induced solvent is reached to the second recording medium through the first recording medium and the coloring substance coated on the second recording medium is colored to form a copied image.
Disadvantages of the above mentioned art are described below. In a commodity distributing business or a material handling field or the like, there are much amount of demand for making a concurrent copying and recording of three to four or more overlapped recording media. In the thermal driving system disclosed in the gazette of Japanese Patent Laid-Open No. Sho 52-115229 indicated in the prior art, there is a certain limitation in heat energy capable of being supplied by the thermal head and there remain many technical problems which must be resolved such as a lack of concentration of image or lack of fineness of image caused by a heat conductivity of the recording medium and a thermal dispersion during its conduction, and a reduction in an image forming speed or the like.
In addition, the ink-jet type recording system described in the gazettes of Japanese Patent Laid-Open No. Sho 51-24833 and Japanese Patent Publication No. Sho 2-37307 indicated in the prior art have some problems of permeation of either liquid ink or coloring induced solvent through the recording medium or dispersion of either liquid ink or coloring induced solvent in the recording medium and the recording system described in the gazette of Japanese Patent Laid-Open No. Sho 55-69463 has a certain limitation in an amount of heat energy carried by ink particles and as for the application requiring copying of 3 to 4 or more sheets, there remain many technical problems in view of their practical applications.